用热电LTQ线性离子阱质谱分析人参皂苷，负电扫描模式下目标离子799响应值有10×6级，单选799离子时响应值就比较正常，有10×5级
同目标物正电扫描模式下离子801响应值可达10×6级，为何单选801离子时在不加碰撞能量下响应值显著降低到10×1级？求赐教[img=,690,525]https://ng1.17img.cn/bbsfiles/images/2019/09/201909172102111840_9887_1644700_3.png!w690x525.jpg[/img][img=,690,525]https://ng1.17img.cn/bbsfiles/images/2019/09/201909172102111840_9887_1644700_3.png!w690x525.jpg[/img]